Make function proxies work as constructors.

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index a34232310c325688e797419d7d900ee2f4125de0..0668c0892bc97044184a1dbabb89c94c746d19bc 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -80,12 +80,12 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   //  -- edi: constructor function
   // -----------------------------------
 
-  Label non_function_call;
+  Label slow, non_function_call;
   // Check that function is not a smi.
   __ JumpIfSmi(edi, &non_function_call);
   // Check that function is a JSFunction.
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
-  __ j(not_equal, &non_function_call);
+  __ j(not_equal, &slow);
 
   // Jump to the function-specific construct stub.
   __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
@@ -95,10 +95,19 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
 
   // edi: called object
   // eax: number of arguments
+  // ecx: object map
+  Label do_call;
+  __ bind(&slow);
+  __ CmpInstanceType(ecx, JS_FUNCTION_PROXY_TYPE);
+  __ j(not_equal, &non_function_call);
+  __ GetBuiltinEntry(edx, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
+  __ jmp(&do_call);
+
   __ bind(&non_function_call);
+  __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+  __ bind(&do_call);
   // Set expected number of arguments to zero (not changing eax).
   __ Set(ebx, Immediate(0));
-  __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
   Handle<Code> arguments_adaptor =
       masm->isolate()->builtins()->ArgumentsAdaptorTrampoline();
   __ SetCallKind(ecx, CALL_AS_METHOD);